There are numerous studies and reports on the negative side-effects/risk factors for both the mother AND the child concerning late pregnancies. @appletree123157, I'd reccommend having a look on the internet, aswell as trying to get your hands on some books in which discuss the matter. Its definately worth gaining a little knowledge on before you decide which avenue you would like to take to obtain a child (whether your own egg, someone elses, or adoption etc.)
From memory- most of the risk factors concern the brain development of the child, and its alot harder for the mother's organs to regenerate (and your hormones to restabilise) after being pregnant at such a late stage. I have some books here at my house, if you like, I will have a quick read right now and list some off for you. Bear with me for a moment..
I think 35 is when someone should stop having children because if that youngest child has children, you want to be able to be there and be a good grandma ^.^ You can't do that and be active with them at, like, 70 years old or older. No offense to anyone out there who is 70 and still rides bikes and such.